Microphone New Modern 21A equivalent for all handsets

These are modern 21A equivalent new microphone for handsets.

 Ideal for 232 telephones also know as a 200 series.Also 332 telephones also know as a 300 series.Candlesticks,wall telephones,746 telephones ,indeed virtually any telephone.

If you take casing off these they can be used in trimphone handsets and even early horn type handsets being smaller again.